Hydraulic valve with adjustable locking device

ABSTRACT

A hydraulic valve includes a sliding control member that delimits at least one constantly adjustable diaphragm. The sliding control member is configured to be moved in the direction of a longitudinal axis. The hydraulic valve further includes a locking device with a locking member that is configured to be moved counter to the force of a first spring transversely relative to the longitudinal axis. The hydraulic valve further includes at least one catch contour in which the locking member is configured to be engaged in such a positive-locking manner that the sliding control member is releasably retained in a catch position that is associated with the respective catch contour. The position of at least one catch contour is constantly adjustable in such a manner that the free cross-sectional surface-area of the at least one diaphragm is constantly adjustable in the associated catch position.

This application claims priority under 35 U.S.C. §119 to patentapplication no. DE 10 2015 210 129.0, filed on Jun. 2, 2015 in Germany,the disclosure of which is incorporated herein by reference in itsentirety.

BACKGROUND

The disclosure relates to a hydraulic valve.

A hydraulic valve is known from DE 39 23 743 A1. The valve has a slidingcontrol member which can be moved in the direction of a longitudinalaxis and which delimits a constantly adjustable diaphragm. There isfurther provided a locking device which has a locking member which canbe moved counter to the force of a first spring transversely relative tothe longitudinal axis. There are further provided two catch contours inwhich the locking member can be engaged in such a positive-lockingmanner that the sliding control member is releasably retained in a catchposition which is associated with the respective catch contour.

It is further known to steplessly adjust the volume flow in the catchpositions by means of a separate, constantly adjustable diaphragm.

SUMMARY

An advantage of the valve proposed is that the volume flow in at leastone catch position is constantly adjustable. The valve is furtherconstructed in a particularly simple manner. In particular, it ispossible to dispense with the separate, constantly adjustable diaphragmfor adjusting the volume flow in the catch position. Furthermore, thevalve is particularly space-saving.

In accordance with the disclosure, it is proposed that the position ofat least one catch contour be constantly adjustable in such a mannerthat the free cross-sectional surface-area of the at least one diaphragmis constantly adjustable in the associated catch position. The slidingcontrol member is thus in the catch position from the outset in aposition in which the associated constantly adjustable diaphragm on thesliding control member has the free cross-sectional surface-area whichis required in order to adjust the desired volume flow.

The hydraulic valve preferably has a housing having a pump connectionlocation and at least one operating connection location and, if desired,a tank connection location, wherein the connection locations mentionedcan be connected to each other in fluid terms in accordance with theposition of the sliding control member via the at least one diaphragm. Afluid channel system is preferably provided in the housing for thispurpose. The locking member and the first spring may optionally bereceived in the housing or in the sliding control member, wherein thecatch contour is arranged on the other component, the sliding controlmember or housing, respectively. The locking member is preferablynon-movable in the direction of the longitudinal axis with respect tothe portion in which it is received.

Advantageous developments and improvements of the disclosure are set outin the dependent claims.

There may be provision for a first catch contour to be securely arrangedon an outer peripheral face of the sliding control member, wherein itextends helically with respect to the longitudinal axis, wherein therotation position of the sliding control member is constantly adjustablewith respect to the longitudinal axis. Consequently, the freecross-sectional surface-area of the at least one diaphragm in therespective catch position can be constantly adjusted by rotating thesliding control member. The pitch of the helical line which isassociated with the first catch contour may be constant or variablealong the longitudinal axis.

There may be provided two first catch contours which are associated withdifferent catch positions and which have an opposing pitch direction.The first two catch contours are preferably associated with twooperating positions of the valve sliding member, in which positions theactuator which is connected to the valve has opposing movementdirections. As a result of the proposed configuration of the catchcontours, it is possible for the volume flow in the catch positions ofthe two operating positions to be adjusted in the same manner when thesliding control member is rotated.

There may be provision for a second catch contour to be securelyarranged on the outer peripheral face of the sliding control member insuch a manner that the first and the second catch contours definedifferent catch positions, wherein the second catch contour extends inan annular manner with respect to the longitudinal axis. The secondcatch contour is preferably associated with a free-running position ofthe valve, in which the actuator which is connected to the valve canmove freely.

There may be provided a separate first adjustment member which issecured in a rotationally adjustable manner on the outer side of ahousing of the hydraulic valve, wherein the sliding control member iscoupled in terms of movement to the first adjustment member with respectto a rotation. Consequently, the free cross-sectional surface-area ofthe at least one diaphragm in the respective catch position can beconstantly adjusted by rotating the first adjustment member. The firstcatch member is readily accessible for the user of the valve. Thecorresponding rotation movement is transmitted by the proposed movementcoupling to the sliding control member. The first adjustment member canpreferably be rotationally adjusted with respect to the longitudinalaxis. The sliding control member can preferably be displaced in thedirection of the longitudinal axis with respect to the first adjustmentmember.

There may be provision for the first adjustment member to be constructedin a pot-like manner, wherein there is arranged within the firstadjustment member a second spring which acts on the sliding controlmember in the direction of the longitudinal axis. Consequently, thefirst adjustment member further serves to protect the second spring fromenvironmental influences.

There may be provision for the locking member and the first spring to bereceived in the sliding control member, wherein at least one catchcontour is arranged on a separate second adjustment member which issecured to a housing of the hydraulic valve so as to be adjustable in alinear manner with respect to the longitudinal axis. Consequently, thefree cross-sectional surface-area of the at least one diaphragm in therespective catch position can be constantly adjusted by displacing thesecond adjustment member in the longitudinal direction.

There may be provision for the at least one catch contour to beconstructed in a rotationally symmetrical manner with respect to thelongitudinal axis. Such a catch contour can be produced in aparticularly simple manner by means of a rotational processingoperation.

There may be provision for the second adjustment member to have a threadwhose center axis coincides with the longitudinal axis, wherein thethread is in screwed engagement with a counter-thread on the housing.The linear adjustability of the second adjustment member can thereby beproduced in a particularly simple manner. There may be provided acounter-nut which is in screwed engagement with the thread or with thecounter-thread, wherein the second adjustment member can be clamped tothe housing by means of the counter-nut.

There may be provision for a separate union nut to be provided which isin screwed engagement with the housing in such a manner that it can bemoved in the direction of the longitudinal axis, wherein the union nutis coupled to the second adjustment member in terms of movement in thedirection of the longitudinal axis. The union nut may be arranged on thehousing in a particularly flexible manner so that it is readilyaccessible for the user.

Of course, the features mentioned above and those intended to beexplained below can be used not only in the combination set out in eachcase, but also in other combinations or alone, without departing fromthe scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is explained in greater detail below with reference tothe appended drawings, in which:

FIG. 1 shows a hydraulic drive system having a valve according to afirst embodiment of the disclosure;

FIG. 2 shows a hydraulic drive system having a valve according to asecond embodiment of the disclosure; and

FIG. 3 shows a hydraulic drive system having a valve according to athird embodiment of the disclosure.

DETAILED DESCRIPTION

FIG. 1 shows a hydraulic drive system 10 having a valve 20 according toa first embodiment of the disclosure. The drive system 10 comprises anactuator 11 which is constructed, for example, as a hydraulic cylinderor a hydraulic motor, wherein it is connected to the two operatingconnection locations 31 of the valve 20. Furthermore, there is provideda pump 12 which is connected to the pump connection location 32 of thevalve 20. Furthermore, there is provided a tank 13 which is connected tothe tank connection location 33 of the valve 20.

The valve 20 comprises a locking device 60 which is illustrated indetail, wherein the remaining valve is indicated only schematically. Thecorresponding transition location is indicated with the referencenumeral 51. The valve 20 has in this instance four switching positionsand may, for example, be used in an agricultural tractor. In the lockingposition 22, all four connection locations 31; 32; 33 are locked so thatthe actuator 11 is hydraulically clamped in a non-movable manner. In thefirst operating position 23, the actuator 11 is deployed, with it beingretracted in the second operating position 24. To this end, pressurizedfluid is drawn from the pump 12 out of the tank 13 in each case andconveyed via the valve 20 to one side of the actuator 11, whereinpressurized fluid flows from the opposite side back to the tank 13. Inthe free-running position 25, the actuator 11 can be freely moved,wherein excess pressurized fluid flows to the tank 13 or lackingpressurized fluid is drawn from the tank 13. The free-running position25 is, for example, required for the lifting mechanism of the tractormentioned when the attachment which is fitted thereto is intended torest on the ground with at least a portion of its inherent weight.

The sliding control member 40 of the valve 20 is retained by the secondspring 42 in the non-actuated state in the locking position 22. With theactuation device 50 which is constructed in this instance as a manualactuation member, the sliding control member 40 can be moved into theremaining positions 23; 24; 25, wherein there is associated in thisinstance with each of these positions a catch position in which thesliding control member is retained counter to the restoring force of thesecond spring 42 by the locking device 60. As a result of acorrespondingly large actuation force on the actuation device 50, theretention force of the locking device 60 can be overcome so that thesliding control member 40 can be moved further.

The valve 20 is constructed in this instance as a proportional valve,wherein it has a constantly adjustable diaphragm 41 which is arranged inthe flow path which contains the pump connection location 32. The valve20 according to the disclosure has the advantage that the freecross-sectional surface-area of this diaphragm 41 can be adjustedconstantly at least in a portion of the catch positions.

The locking device 60 has a spherical locking member 61, which can bemoved transversely relative to the longitudinal axis 21. The lockingmember 61 is in this instance pressed by a pretensioned first spring 64in the direction of the sliding control member 40. The pressing force ofthe first spring 64 acts in this instance indirectly via a tappet 65 onthe locking member 61 so that jamming is prevented.

The partially circular-cylindrical tappet 65 is in this instance guidedin a linearly movable manner in an adapted circular-cylindrical holeperpendicularly with respect to the longitudinal axis 21. At the sideremote from the locking member 61, the first spring is supported on anabutment member 66 and a closure screw 67. The outer peripheral face ofthe abutment member 66 has, for example, a hexagonal cross-sectionalshape which is received in an adapted recess perpendicularly relative tothe longitudinal axis so as to be linearly movable and non-rotational.The closure screw 67 is screwed into the housing 30 of the valve 20,wherein the rotating screw movement cannot be transmitted to the firstspring 64 as a result of the rotationally secure abutment member 66.

On the sliding control member 40 there are arranged a total of threecatch contours 70 in which the locking member 61 can selectively engagein a positive-locking manner. The catch contours 70 are each constructedin the form of grooves with a constant, trapezoidal cross-sectionalshape. The first two catch contours 71 extend in a helical manner withrespect to the longitudinal axis so that, in the corresponding catchpositions, the free cross-sectional surface-area of the diaphragm 41 canbe adjusted by rotating the sliding control member 40. The first twocatch contours 71 have an opposing pitch direction. The second catchcontour 72 is associated with the free-running position 25 in which thediaphragm 41 is preferably closed, wherein an adjustment is notrequired. The second catch contour 72 is therefore constructed in anannular manner with respect to the longitudinal axis 21.

The second spring 42 is constructed between a first and a second springplate 43; 44 with pretensioning. The first spring plate 43 is supportedin the locking position 22 illustrated in FIG. 1 in the direction of thelongitudinal axis 21 directly on the sliding control member 40, whereinthe second spring plate 44 is supported in the opposite direction on aseparate spacer screw 47. The spacer screw 47 is screwed into thesliding control member 40 and secured against release.

The first spring plate 43 is further supported on the housing 30. If thesliding control member 40 is moved to the left in FIG. 1, the firstspring plate 43 is supported only on the housing 30. If the slidingcontrol member 40 is moved in the opposite direction, the first springplate 43 is supported only on the sliding control member 40. The secondspring plate 44 is further supported on a first adjustment member 80which surrounds the second spring 42 and the first and the second springplate 43; 44 in a pot-like manner. The first adjustment member 80 issecurely retained on the housing 30 in the direction of the longitudinalaxis 21. If the sliding control member 40 is moved to the left in FIG.1, the second plate spring 43 is supported only on the spacer screw 47,wherein the second spring 42 presses the sliding control member 40 tothe right. If the sliding control member 40 is moved to the right inFIG. 1, the second spring plate 44 is supported only on the firstadjustment member 80, wherein the second spring 42 presses the slidingcontrol member 40 to the left.

The first adjustment member 80 is rotationally adjustable with respectto the longitudinal axis 21 with respect to the housing 30, wherein therotation position thereof can be released or secured with the retentionmember 82. The sliding control member 40 is coupled in terms of movementto the first adjustment member 80 in terms of rotation about thelongitudinal axis 21, wherein the portions mentioned can be movedrelative to each other in the direction of the longitudinal axis 21. Tothis end, the inner peripheral face 81 of the first adjustment member 80may have a hexagonal cross-sectional shape in which an associated outerperipheral face 45 of the second spring plate 44 engages in apositive-locking manner. The mentioned outer peripheral face 45 may alsohave a hexagonal cross-sectional shape. In a similar manner, an innerperipheral face 46 of the second spring plate 44 may have a hexagonalcross-sectional shape which engages in a positive-locking manner in anassociated outer peripheral face 48 of the spacer screw 47. Thecross-sectional shape of the last-mentioned outer peripheral face 48 mayalso be constructed in a hexagonal manner.

Reference should also be made to the various sealing rings 35.

FIG. 2 shows a hydraulic drive system 110 having a valve 120 accordingto a second embodiment of the disclosure. The second embodiment isconstructed in an identical manner to the first embodiment according toFIG. 1 with the exception of the differences described below so thatreference may be made to the explanations relating to FIG. 1 in thisregard. In this instance, in FIG. 2, those components which are presentin FIG. 1 in an identical or corresponding manner are indicated with thesame reference numeral increased by 100.

In the second embodiment of the valve 120, the spherical locking member161 and the first spring 164 are arranged inside the sliding controlmember 140, wherein the catch contours 170 are arranged on the housing130. The locking member 161 can be moved transversely relative to thelongitudinal axis 121, wherein the force of the first spring 164 acts inthe direction of the longitudinal axis 121. The corresponding forceredirection is brought about by means of the cone 163 which is supportedon the first spring 164, wherein the corresponding face which iscircular-cone-like with respect to the longitudinal axis 121 abuts anauxiliary ball 162 which in turn is in abutment with the locking member161. It is thereby ensured that the locking member 161 is retained in areliable manner in each position by the associated hole in the slidingcontrol member 140 in the direction of the longitudinal axis 121.

The second spring 142 operates in a similar manner to the firstembodiment, wherein the second spring plate 144 is also supported on thehousing 130 in the longitudinal direction 121. The housing 130 isconstructed in several parts so that the second spring 142 and the twospring plates 143; 144 can be mounted. The locking member 161 and theauxiliary ball 162 are further received in the spacer screw 147. Thespacer screw 147 extends for this reason in the direction of thelongitudinal axis 121 beyond the second spring 142.

The two catch contours 170 are arranged on a separate second adjustmentmember 190 which inter alia surrounds the locking member 161 and thespacer screw 147 in a pot-like manner. The second adjustment member 190is provided with a thread 191 which is constructed in this instance asan inner thread. The thread 191 is screwed onto a counter-thread 134 onthe housing 130 which is constructed in this instance as an outerthread. By the second adjustment member 190 being rotated, the two catchcontours 170 can be steplessly displaced in the direction of thelongitudinal axis 121 relative to the housing 130. The position of thesecond adjustment member 190 may if desired be secured with acounter-nut (not illustrated).

The two catch contours 170 are each constructed as faces which arecircular-cone-like with respect to the longitudinal axis 121. When thelocking member 170 engages in the left-hand catch contour 170 in FIG. 2,the sliding control member 140 is located in the second operatingposition 124. When the locking member 170 engages in the right-handcatch contour 170 in FIG. 2, the sliding control member 140 is locatedin the first operating position 123. A rotation of the second adjustmentmember 190 then brings about a displacement of the sliding controlmember 140 in the direction of the longitudinal axis 121 so that thefree cross-sectional surface-area of the diaphragm 141 constantlychanges.

FIG. 3 shows a hydraulic drive system 210 having a valve 220 accordingto a third embodiment of the disclosure. The third embodiment, with theexception of the differences described below, is constructed in anidentical manner to the second embodiment according to FIG. 2 or thefirst embodiment according to FIG. 1 so that reference may be made tothe explanations relating to FIG. 2 and FIG. 1 in this regard. In thisinstance, in FIG. 3, those components which are present in FIG. 2 in anidentical or corresponding manner are indicated with the same referencenumeral increased by 100, wherein the reference numerals with respect toFIG. 1 are accordingly increased by 200.

Preferably, four locking members 261 are arranged so as to be offsetthrough 90° with respect to the longitudinal axis 221. Two opposinglocking members 261 are associated with the second adjustment member290, wherein the other two locking members 261 are associated with thecatch extension 295. The former ones are used for engagement in theoperating positions 223 and 224, the latter ones for engagement in thefree-running position 225.

The locking member 261 and the second spring are, as in the secondembodiment, arranged in the sliding control member 240. The primarydifference is the relative position between the second spring 242 andthe closure member 261. The second spring 242 is now arranged at theoutermost end of the sliding control member 240, whereas the closuremember is arranged so as to be offset with respect to the second spring242 relative to the center of the sliding control member 240. In thesecond embodiment, the relationships are precisely reversed. The secondspring 242 is covered by means of a pot-like protective cap 294 whichforms a non-movable portion of the multi-component housing 230. Theseparate second adjustment member 290 is received so as to be protectedinside the protective cap 294, wherein it is movable in the direction ofthe longitudinal axis 221 with respect to the housing 230 or theprotective cap 294. The two catch contours 270 on the second adjustmentmember 290 are constructed in an identical manner to the secondembodiment.

The second adjustment member 290 is guided in a groove of the guidingsleeve 296. This also constitutes the catch extension 295 for theengagement of the free-running position 225.

The second adjustment member 290 is securely connected to a pin-likecarrier 293, which protrudes from the protective cap 294 through anelongate hole. As a result of the carrier 293, the second adjustmentmember 290 is prevented inter alia from rotating with respect to thehousing 230 or the protective cap 294. Furthermore, the carrier 293 isin carrying engagement in the direction of the longitudinal axis 221with a union nut 292 which is screwed onto the protective cap 294 at theouter side. The carrier member 293 engages to this end in a groove whichextends in an annular manner about the longitudinal axis 221 on an innerperipheral face of the union nut 292. A rotation of the union nut 293brings about the displacement thereof in the direction of thelongitudinal axis 221. This displacement is transmitted via the carrier293 to the second adjustment member 290 so that the catch contours 270at that location are displaced in the direction of the longitudinal axis221.

Reference should also be made to the catch extension 295. This ispreferably constructed on a separate guiding sleeve 296, which issecurely connected to the protective cap 294 so that the catch extension295 cannot be moved in the direction of the longitudinal axis 221. Thecatch extension 295 also forms a catch contour 270 with which thelocking member 261 can be engaged, wherein the corresponding catchposition corresponds to the free-running position 225. The catchextension 295 consequently has the same function as the second catchcontour in the first embodiment.

LIST OF REFERENCE NUMERALS

-   -   10; 110; 210 Drive system    -   11; 111; 211 Actuator    -   12; 112; 212 Pump    -   13; 113; 213 Tank    -   20; 120; 220 Valve    -   21; 121; 221 Longitudinal axis    -   22; 122; 222 Locking position    -   23; 123; 223 First operating position    -   24; 124; 224 Second operating position    -   25; 125; 225 Free-running position    -   30; 130; 230 Housing    -   31; 131; 231 Operating connection location    -   32; 132; 232 Pump connection location    -   33; 133; 233 Tank connection location    -   134 Counter-thread    -   35; 135; 235 Sealing ring    -   40; 140; 240 Sliding control member    -   41; 141; 241 Diaphragm    -   42; 142; 242 Second spring    -   43; 143; 243 First spring plate    -   44; 144; 244 Second spring plate    -   45 Outer peripheral face of the second spring plate (hexagonal)    -   46 Inner peripheral face of the second spring plate (hexagonal)    -   47; 147; 247 Spacer screw (securely screwed into the sliding        control member)    -   48 Outer peripheral face of the spacer screw (hexagonal)    -   50; 150; 250 Valve actuation    -   51; 151; 251 Connection (between sliding member portion which is        shown schematically and in detail)    -   52 Outer peripheral face of the sliding control member    -   60; 160; 260 Locking device    -   61; 161; 261 Locking member    -   162; 262 Auxiliary ball    -   163; 263 Cone    -   64; 164; 264 First spring    -   65 Tappet    -   66 Abutment member    -   67 Closure screw    -   70; 170; 270 Catch contour    -   71 First catch contour    -   72 Second catch contour    -   80 First adjustment member    -   81 Inner peripheral face of the first adjustment member        (hexagonal)    -   82 Retention member (for rotationally adjustable retention of        the first adjustment member)    -   190; 290 Second adjustment member    -   191 Thread    -   292 Union nut    -   293 Carrier    -   294 Protective cap    -   295 Catch extension    -   296 Guiding sleeve

What is claimed is:
 1. A hydraulic valve, comprising: a sliding controlmember that is configured to be moved in the direction of a longitudinalaxis and that delimits at least one constantly adjustable diaphragm; alocking device having a locking member configured to be moved counter tothe force of a first spring transversely relative to the longitudinalaxis; and at least one catch contour in which the locking member isconfigured to be engaged in such a positive-locking manner that thesliding control member is releasably retained in a catch position thatis associated with the respective catch contour, wherein a position ofat least one catch contour is constantly adjustable in such a mannerthat a free cross-sectional surface-area of the at least one diaphragmis constantly adjustable in the associated catch position; wherein theat least one catch contour includes a first catch contour that issecurely arranged on an outer peripheral face of the sliding controlmember, the first catch contour extending helically with respect to thelongitudinal axis, and wherein a rotation position of the slidingcontrol member is constantly adjustable with respect to the longitudinalaxis.
 2. The hydraulic valve according to claim 1, wherein the firstcatch contour includes two first catch contours that are associated withdifferent catch positions and that have an opposing pitch direction. 3.The hydraulic valve according to claim 1, wherein: the at least onecatch contour includes a second catch contour that is securely arrangedon the outer peripheral face of the sliding control member such that thefirst catch contour and the second catch contour define different catchpositions, and the second catch contour extends in an annular mannerwith respect to the longitudinal axis.
 4. The hydraulic valve accordingto claim 1, further comprising: a housing; and a separate firstadjustment member secured in a rotationally adjustable manner on anouter side of the housing, the sliding control member coupled in termsof movement to the first adjustment member with respect to a rotation.5. The hydraulic valve according to claim 4, wherein: the firstadjustment member is configured in a pot-like manner, and a secondspring is arranged within the first adjustment member, the second springacting on the sliding control member in the direction of thelongitudinal axis.